From d5f630db6c034fa568bd0e35b4f2ba24e2fc6744 Mon Sep 17 00:00:00 2001
From: Navraj Lalli <navrajsinghlalli@gmail.com>
Date: Mon, 30 Sep 2024 12:28:16 +0100
Subject: [PATCH] Fix sign used for atom-style potential

A positive sign in front of the electric potential is consistent with
E = -grad(electric potential).
---
 src/REAXFF/fix_qeq_reaxff.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/REAXFF/fix_qeq_reaxff.cpp b/src/REAXFF/fix_qeq_reaxff.cpp
index adaf5be031..37e90f582e 100644
--- a/src/REAXFF/fix_qeq_reaxff.cpp
+++ b/src/REAXFF/fix_qeq_reaxff.cpp
@@ -1158,7 +1158,7 @@ void FixQEqReaxFF::get_chi_field()
     for (int i = 0; i < nlocal; i++) {
       if (mask[i] & efgroupbit) {
         if (region && !region->match(x[i][0],x[i][1],x[i][2])) continue;
-        chi_field[i] = -efield->efield[i][3];
+        chi_field[i] = efield->efield[i][3];
       }
     }
   }